JP2783211B2 - Magnetic head assembly and magnetic disk drive using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic head assembly and a magnetic disk drive used in a magnetic disk drive.

[0002]

2. Description of the Related Art A magnetic head assembly of a magnetic disk drive includes a slider, a suspension, and a slider and a suspension.
And an arm for transporting to a predetermined position. The slider includes an electromagnetic transducer that converts magnetic recording on a magnetic medium into an electric signal. The electric signal is transmitted via a flexible printed circuit (FPC). The FPC is fixed on the arm via an adhesive layer, and a GND pattern (ground pattern) of the FPC conductive pattern is electrically connected to the arm via a screw or a pin.
By keeping the pattern and the arm at the same potential, the reliability of the magnetic circuit and the electric circuit is increased.

[0003]

In this prior art, the ambient temperature surrounding the magnetic head assembly rises to 60 to 80 degrees during the operation of the magnetic disk drive, so that the magnetic head assembly malfunctions and the This has led to a decrease in reliability, such as writing of erroneous information in magnetic recording.

[0004] The reason is described below. Since the inside of the magnetic disk device becomes extremely hot during operation, the adhesive layer fixing the FPC and the arm melts and flows out. As a result, the adhesive fills the gap between the arm hole and the screw or pin serving as the conductive medium, and poor conduction occurs between the two.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic head assembly which does not have the above-described problems and can reliably establish an electrical connection between an FPC and an arm even in a high-temperature environment.

[0006]

According to the present invention, there is provided a magnetic head assembly comprising: a flexible print circuit (FPC);
An arm which is electrically connected to a GND pattern among the conductive patterns formed on the FPC via screws or pins, and which fixes the FPC via an adhesive layer; a suspension held by the arm; A hole for inserting a screw or a pin is provided in the adhesive layer and the arm, and a hole diameter of the adhesive layer is larger than a hole diameter of the arm side. I do.

In the following embodiments of the present invention, the hole diameter of the adhesive layer is at least twice the hole diameter on the arm side, or The magnetic head assembly is configured so that the adhesive layer is not stuck to the area smaller than double.

[0008] The present invention is characterized in that the arm and the FPC are electrically connected by a conductive adhesive applied to the hole on the arm side.

Further, a magnetic disk drive according to the present invention is characterized in that the magnetic head assembly is mounted.

During operation, the inside of the magnetic disk device becomes extremely hot, and the adhesive layer fixing the FPC and the arm melts and flows out. However, in the magnetic head assembly of the present invention, since the hole diameter of the adhesive layer is configured to be larger than the hole diameter of the arm side, the adhesive fills the gap between the screw or the pin serving as a conductive medium and the arm hole. Without this, it is possible to reliably establish an electrical connection between the two.

[0011]

Next, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a magnetic head assembly according to the first embodiment.

The magnetic head assembly of the invention shown in FIG. 1 includes a slider 1, a suspension 2, an arm 3, and an FPC 5. The slider 1 is attached to a suspension 2 having elasticity, and is elastically held on a magnetic medium. The suspension 2 is held on an arm 3 for holding or transporting it to a predetermined position. The slider 1 includes an electromagnetic transducer, and converts magnetic information into an electric signal, which is transmitted via the fine wire 4 and the FPC 5.

FIG. 2 shows a cross section of a connecting portion between the FPC 5 and the arm 3. In order to keep the electrostatic potential of the electric circuit constant, the GND pattern of the conductive patterns of the FPC 5 and the arm 3 are electrically connected via the screw 6. FPC 5 is a sheet-like adhesive 9 as an adhesive layer.
(A normal adhesive may be used, but it is better to use it.) The FPC 5 is electrically connected to the arm 3 using the screw 6 as a medium. The screw 6 is soldered to the GND pattern of the FPC 5 and screwed to the arm 3 to be fixed and connected.

The FPC 5 has a three-layer structure in which a conductor (copper) 8 is sandwiched between polyimides 7. Here, the hole diameter of the sheet adhesive 9 provided as a passage hole for the screw 6 is made larger than the screw hole on the arm 3 side. This hole diameter is preferably at least twice the diameter of the screw hole on the arm side.

FIG. 3 is a sectional view showing a connection portion between the FPC 5 and the arm 3 in the second embodiment.
In this case, in order to further enhance the reliability, the conductive adhesive 10 is applied to the screw hole on the arm 3 side of the magnetic head assembly and screwed.

The other parts are the same as in the structure of the first embodiment.

During operation of the magnetic disk drive, the ambient temperature surrounding the magnetic head assembly rises to 60 to 80 ° C., and this rise in temperature lowers the viscosity of the sheet-like adhesive 9, causing the adhesive 9 to melt and flow out. Occurs. However, when the magnetic head assemblies according to the first and second embodiments of the present invention are used, the adhesive 9 has a structure surrounded by the FPC 5 and the arm 3 as can be seen from FIG. 2 or FIG. Since the adhesive 9 that has flowed out cannot flow into the screw hole on the arm 3 side, the electrical connection between the conductive pattern on the FPC 5 and the arm 3 is maintained reliably, and the high reliability of the magnetic circuit and the electric circuit is maintained. It is possible to

In the case of the second embodiment, since the conductive adhesive is already buried in the gap between the screw and the arm, even if the sheet-like adhesive 9 flows into the screw hole, the electrical connection is made. Disconnection can be prevented.

[0020]

The effect of the present invention is that, under severe high temperatures in a magnetic disk drive, reliable electric connection between the FPC and the arm can be achieved, and high reliability of the magnetic circuit and the electric circuit is maintained. What you can do.

The reason is that, according to the magnetic head assembly of the present invention, the hole diameter of the adhesive layer is made larger than the screw hole on the arm side (more than twice the screw hole diameter on the arm side) or in addition to the arm. This is because a conductive adhesive is applied to the side screw holes.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic head assembly according to first and second embodiments.

FIG. 2 is a cross-sectional view illustrating a connection portion between the FPC and the arm according to the first embodiment.

FIG. 3 is a sectional view showing a connection portion between an FPC and an arm according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slider 2 Suspension 3 Arm 4 Fine wire 5 FPC 6 Screw (Ground screw) 7 Polyimide 8 Copper 9 Adhesive layer (Sheet adhesive) 10 Conductive adhesive

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 21/02 G11B 5/60 G11B 33/14

Claims (4)

(57) [Claims] 1. A flexible print circuit (FP)
C), an arm electrically connected to a conductive pattern formed on the FPC via a screw or a pin, and the FPC fixed to the FPC via an adhesive layer; a suspension held by the arm; In a magnetic head assembly including a magnetic head held by a suspension, a hole for inserting a screw or a pin is provided in the adhesive layer and the arm, and a hole diameter of the adhesive layer is larger than a hole diameter of the arm side. A magnetic head assembly characterized by being large. 2. The magnetic head assembly according to claim 1, wherein the arm and the FPC are electrically connected by a conductive adhesive applied to the hole on the arm side. 3. A magnetic disk drive on which the magnetic head assembly according to claim 1 is mounted. 4. A magnetic disk drive on which the magnetic head assembly according to claim 2 is mounted.